Mr. Velazco made snacks in separate gift bags. He gave one each to the 636 sixth grade students going on the field trip. Then he gave 40 bags to the students in Mrs. Barker's class for decorating the trophy cases. Next he gave 20 to the students in Mrs. Crow's class for helping during the school play. Mr. Velazco had 7 snacks left. How many snacks did he make?
A. 67
B. 636
C. 703
D. 803